Intravenous medications are given in standardized doses as indicated by the pharmaceutical manufacturer. Currently these standardized doses of medicament are compounded and mixed in intravenous fluid, ideally in a laminar flow hood to limit possible contamination, by one licensed and skilled in the art, prior to delivery of the medicament to a patient. Following mixing, the medicament has only a finite life in its active form depending upon the individual drug (generally one day to one week at room temperature) and must be used within this period after which the medicament loses its activity and must be discarded.
Once mixed and prior to its infusion free air must be removed from the mixing and storage container so as to prevent the inadvertent delivery of free air into a patient's vein with resultant harmful consequences.
Container devices providing separate compartments in a single unit for separately enclosing incompatible materials in such a way that they may be later intermixed are described in U.S. Pat. No. 2,176,923 to Nitardy, U.S. Pat. No. 3,290,017 to Davies, et al., U.S. Pat. No. 3,532,254 to Burke, et al., U.S. Pat. No. 3,608,709 to Pike and U.S. Pat. No. 4,637,061 to Riese. These container devices are not believed to be able to maintain an effective fluid-tight seal or moisture barrier between the various spaces formed within the container for the purposes of preparation and storage of sterile medications. This is caused by the various barriers between the spaces not adequately withstanding the normal rigors of packaging, handling and shipping. If the fluid-tight seal or moisture barrier between the storage spaces is broken, premature mixing of the materials may occur which then renders them ineffective for eventual use. Additionally, for containers used in health care situations, sterility of the materials to be mixed must be strictly maintained.
Container devices are described in U.S. Pat. No. 4,458,811 to Wilkinson and U.S. Pat. No. 4,608,043 to Larkin. In these devices designed for intravenous fluid storage and mixing, there is employed a system designed around a central partition with a weakened portion that is frangible with direct external compression. Upon rupture of the weakened portion, the medicament is mixed with the diluent. Uncertainty exists as to the integrity of the weakened portion in the partition so as to guarantee a fluid-tight seal or moisture barrier that will withstand both the rigors of storage and handling, yet allow the weakened portion to be easily broken. There is also a question whether a sufficiently large opening is formed in the frangible section to allow easy mixing of substantially all of a powdered medicament with the diluent liquid. This stems from the fact that the requirements for such a seal are mutually incompatible. A strong seal is needed to prevent moisture transfer and to enable the seal to withstand the rigors of handling and storage. Yet the seal must be easily rupturable to form an opening large enough to allow complete intermixing of the components. Further, in these designs, any air or other gas within the container cannot be separated from the medicament infusion fluid after mixture.